Composite nozzle cap

• US 7,927,094 B2
• Filed: 04/10/2007
• Issued: 04/19/2011
• Est. Priority Date: 04/10/2006
• Status: Active Grant

• Current Assignee: Stacktech Systems Limited
• Original Assignee: Stacktech Systems Limited
• Inventors: Berceanu, Mihai, Fong, Gary
• Primary Examiner(s): Del Sole; Joseph S
• Assistant Examiner(s): BODAWALA, DIMPLE N
• Application Number:
  US11/733,267
• Publication Number:
  US 20070243285A1
• Time in Patent Office: 1,470 Days
• Field of Search: 425562-566, 425/549, 425/192.R, 264/328.15, 264/328.9
• US Class Current: 425/549
• CPC Class Codes: B29C 2045/2787 Nozzle tips made of at least 2 different materials
• CPC Class Codes: B29C 45/278 Nozzle tips B29C45/2735 takes precedence

Abstract

The present invention provides a composite nozzle cap having a first part made of metal and an outer tip of a polymeric material. The first part mechanically secures the nozzle into the nozzle housing by engaging the nozzle housing and pressing against a base flange on the nozzle to clamp the flange between the first part of the nozzle housing. The second part extends away from the nozzle housing and is mechanically secured to the first part. An inner face of the second part contacts the nozzle tip to prevent melt flow between the second part of the nozzle tip. An outer face of the second part contacts the gate insert to avoid melt flow between the second part and the gate insert. As the second part is of a polymeric material, it avoids the heat transfer concerns associated with a metallic interface between the nozzle tip and the gate insert.

Claims

1. A nozzle cap for securing an injection molding nozzle tip to a nozzle housing and extending into a gate insert, said nozzle tip having an inner end opposite an outer end, said inner end having a securing flange extending radially outwardly thereabout, for clamping securement between said nozzle cap and said nozzle housing, said nozzle cap comprising:

a first part having a housing end opposite a connector end with a passage therethrough for receiving said nozzle tip, said housing end being dimensioned to engage said securing flange, said first part having a threaded portion for threadedly engaging said nozzle housing for said clamping securement;

a second part secured at a first end to said connector end of said first part and having a recess for receiving said nozzle tip, said second part having a tip end opposite said first end with an outlet passage therethrough for registering with a melt outlet of said nozzle tip to pass melt emerging from said melt outlet;

said tip end of said second part being dimensioned to sealingly engage said outer end of said nozzle tip and said gate insert such that there is no space between said tip end and said nozzle tip and between said tip end and said gate insert in order to prevent melt flow between said tip end and said outer end of said nozzle tip and between said tip end and said gate insert;

said second part being of a thermoplastic polymer useable at a selected operating temperature of said nozzle tip.

2. The nozzle cap of claim 1 further comprising interactive engagement means acting between said first part and said second part to mechanically secure said second part to said first part.

3. The nozzle cap of claim 2 wherein:

said first end of said second part is insertable into said passage at said connector end;

said interactive engagement means is at least one protrusion on one of said first and second parts which is received in at least one recess on the other of said first and second parts.

4. The nozzle cap of claim 3 wherein:

said at least one protrusion extends radially outwardly from said second part adjacent said first end;

said at least one recess extends radially outwardly from said passage into said first part adjacent said connector end;

said at least one protrusion has a tapered guide surface for guiding said protrusion into and along said passage to said recess, as said second part is inserted into said first part, by resiliently deforming an adjoining area of said second part radially inwardly in response to said insertion.

5. The nozzle cap of claim 4 wherein:

said second part is a molded thermoplastic polymer.